The Midwest Industries Combat Rail Free Float M-Lok Handguard features a patented 4140 heat treated torque plate with 6061 aluminum type 3 hard coat anodizing. It includes a continuous mil-std 1913 picatinny top rail with two integral anti-rotation QD sling sockets. It also includes 7 sides of M-Lok, a 5 slot polymer M-Lok rail, and is fully dehorned and deburred. Features4140 Heat Treated Barrel NutBarrel Nut and Wrench IncludedFeatures Patented 4140 Heat Treated Torque Plate6061 Aluminum Type 3 Hard Coat AnodizedContinuous MIL-STD 1913 Picatinny Top railTwo Integral Anti-Rotation QD Sling SocketsSuper Slim 1.5" Outside and 1.3" Inside DiameterSeven Sides of M-Lok5-Slot Polymer M-Lok rail includedFully Dehorned and Deburred